1. Field of the Invention
The invention relates to apparatus for liquid treatment of wafer-shaped articles.
2. Description of Related Art
Semiconductor wafers undergo a variety of wet processing stages during manufacture of integrated circuits. To accommodate such processes, a single wafer may be supported in relation to one or more treatment fluid nozzles by a chuck associated with a rotatable or non-rotatable carrier.
U.S. Pat. Nos. 4,903,717 and 5,513,668 describe such chucks wherein a plurality of pins assemblies arranged in a circular series contact a peripheral edge of the wafer. The contact surfaces of the pin assemblies are eccentric to the rotational axes of the pin assemblies, and can thus be driven in unison by a common ring gear between a radially inward use position and a radially outward loading and unloading position. Commonly-owned copending application U.S. 2010/0206481 describes a variation on such pin assemblies in which the contact surfaces of the pin assemblies support the weight of the wafer, and position the wafer at a fixed height above the upper plate of the chuck.
More recent versions of such chucks have included heating assemblies that are positioned above the upper plate of the chuck but below the level where a wafer is supported, an example of such a chuck being described in commonly-owned copending application U.S. 2013/0061873.
The repair and maintenance of such chucks is relatively complicated and time-consuming, because, in order to replace even one of the pin assemblies, the chuck has to be disassembled from its associated drive and elevating unit, removed from its associated process module, and dismantled to its individual components under clean room conditions. This operation is especially time-consuming in the case of chucks equipped with heating assemblies as identified above, because the entire lamp housing has to be removed before the chuck itself can be removed from its associated drive unit.